The invention concerns an apparatus for printing on individual articles, more particularly dimensionally stable articles such as CDs.
A printing machine which is frequently used for decorating CDs is to be found for example in EP 0 909 728 A1, having a conveyor belt which serves both for the conveyor feed of the articles to be printed upon, and also for conveying away the printed articles. Those articles are supplied in the form of a stack as a magazine. The magazine essentially comprises a bottom member or base from which a post extends upwardly, so that the articles which are each provided with a central opening are fitted on to the post. For the purposes of introducing the articles into the receiving means of the actual printing machine, they are removed from the stack and separated into individual articles and, after complete printing has been effected thereon, collected in a magazine again, in the form of a stack. In general terms, the procedure in that case is such that the empty magazines from which the articles to be printed upon had been individually removed are then used again for collecting a stack of printed articles.
An object of the invention is to provide an apparatus for printing on individual articles such as CDs, which is so designed as to simplify handling of the articles and magazines for same in connection with the operations of separating the articles to be printed upon and introducing them into receiving means of a conveyor arrangement of the printing apparatus and removing printed articles from the conveyor arrangement and collecting those articles in a magazine.
Another object of the present invention is to provide an article-printing apparatus which is of such a configuration that an operator can more easily and safely gain access to functional parts of the apparatus.
Still another object of the present invention is to provide an apparatus for printing on individual CDs in a continuous operating procedure while being of such a design layout that the apparatus can be readily monitored and supervised by an operator.
In accordance with the principles of the present invention an apparatus for printing on dimensionally stable individual articles such as CDs is provided with a conveyor arrangement for transportation of the articles along a first conveyor path. Provided along the conveyor path are at least one printing station, at least one entry station for the articles to be printed upon and a removal station for the printed articles. The articles to be printed upon are transported in a magazine as a stack including a plurality of articles into a separating station and are individually separated therein. The articles are each fitted into a receiving means of the conveyor arrangement and after the printing operation the printed articles are removed in the removal station from the respective receiving means of the conveyor arrangement and assembled in a magazine disposed in a collecting station to form a stack including a plurality of articles, for discharge thereof. A conveyor means conveys the magazines containing the articles to be printed upon in a direction towards the entry station and then conveys the empty magazines in a direction towards the removal station. The apparatus further has at least one transfer arrangement by means of which the articles to be printed upon are individually removed from their magazine and moved in a direction towards the respective receiving means of the conveyor arrangement or the printed articles removed from the respective receiving means of the conveyor arrangement are fed to the magazine for discharge thereof. The conveyor means includes a conveyor belt for conveying the magazines both through the separating station and also through the collecting station. The conveyor belt conveys the empty magazines out of the separating station into the collection station. The transfer arrangement comprises at least one stepwise circulating transfer arrangement for the individual articles, providing a second conveyor path at which are arranged the magazine respectively disposed in the separating station, the receiving means respectively disposed in the receiving station for the article to be printed upon, the respective receiving means respectively disposed in the removal station for the printed article, and the magazine disposed in the collecting station.
Thus the conveyor belt for the magazines transports the magazines both through the separating station for individually separating the articles to be printed upon and also through the collecting station for the printed articles. The articles are individually removed from the magazine in the separating station in the usual manner by the transfer arrangement and moved to the respective receiving means of the conveyor arrangement of the printing machine, and the printed articles are taken from the respective receiving means of the conveyor arrangement and transported to the magazine which is disposed in the collecting station, while the conveyor belt transports the emptied magazines from the separating station into the collecting station for subsequent charging of the magazines with printed articles.
Preferably, the conveyor belt is appropriately in the form of a curved belt and forms an endless conveyor path, thus providing, upstream of the respective magazine in the separating station, an accumulation or buffer space for at least one further magazine filled with articles to be printed upon, in order in that way to form a stock of magazines and, after emptying of the magazine in the separating station, to be able to perform rapid substitution of a filled magazine for an empty magazine. An accumulation space for at least one empty magazine can also be provided upstream of the respective magazine in the collecting station, as considered in the conveyor direction of the conveyor belt. That means that the portion of the second conveyor path which is formed by the conveyor belt and which is between the separating stations and the collecting stations must be of a corresponding length in order to form an accumulation space for the required number of magazines.
An advantage of the invention is that, by virtue of a corresponding prolongation of the conveyor belt, it is possible for the stations at which the magazines filled with the articles to be printed upon are put on to the conveyor belt or the magazines filled with the printed articles are carried away from the conveyor belt to be arranged in such a way that they are easily accessible from the exterior and if possible are disposed in a region in which an operator cannot be in danger due to any rotating parts of the machine or the like. It is also readily possible for those two stations to be arranged at such a small spacing from each other that they can be conveniently monitored and operated by only one operator. It is furthermore also possible for the configuration of the conveyor belt to be so selected that, outside the apparatus or at an edge region of the apparatus it passes through a station in which the magazines provided with printed articles are emptied and thereupon the emptied magazines are filled with articles to be printed upon and the filled magazines are conveyed in a direction towards the separating station.
A simplification which can be achieved by using the invention and the adaptability to the respective circumstances involved, in particular in terms of handling of the magazines, become clear in particular when, in accordance with a further preferred feature of the invention, the apparatus is so designed that a first group of the articles transported by the common conveyor arrangement is printed upon in at least a first printing station and a second group of articles is printed upon in at least a second printing station. Provided for each group of articles is a respective particular entry station for the articles to be printed upon, a removal station for the printed articles, a conveyor belt and a transfer arrangement. With that arrangement therefore there is a complete system for each group of articles so that both groups can be separately introduced into the apparatus and separately removed therefrom again. That is advantageous in particular if the two groups of articles are to be provided with different print images, as is often the usual situation with machines of that kind. There is then no risk that the articles with different printing thereon become mixed up with each other. In addition, the fact that the groups of articles are handled separately means that there is also the possibility of optionally using only one handling arrangement and thus printing upon only one group of articles.
Further objects, features and advantages of the invention will be apparent from the description hereinafter of a preferred embodiment of the invention.